Tray for packaging portions of meat or similar foods

ABSTRACT

The invention relates to a tray for packaging portions of meat or similar foods that are stored and presented in refrigerated conditions. Said tray is deep-drawn from polystyrene or a similar foam material, and has a base and a peripheral side wall. Said base and said side wall have a liquid-impermeable skin on the inside and the outside. This skin has recesses on the inside of the base and the foam layer that is located between the inner and outer skin is at least partially open-celled and has the effect of absorbing liquid. At least one channel is molded in the inside of the base, said channel essentially completely surrounding a section of the surface of the base and having flanks and a channel floor which also have a liquid-impermeable skin. The flank which is oriented towards said section of the surface has at least one recess which allows the passage of liquid.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit, as a National stage entry of a PCTapplication pursuant to 35 U.S.C. §371, of International ApplicationNumber PCT/EP99/09315 filed Nov. 30, 1999, published in the Germanlanguage, which in turn claims priority in its parent case, Germanpatent DE 198 56 494 filed Dec. 8, 1998, both of which are incorporatedby reference herein.

TECHNICAL FIELD

The invention pertains to trays. More particularly, the presentinvention relates to a tray for packaging portions of meat and similarfoods stored and presented in refrigerated conditions.

The invention relates to a tray for packaging portions of meat andsimilar foods stored and presented in refrigerated conditions accordingto the preamble of patent claim 1.

BACKGROUND OF THE INVENTION

It is known to package portions of meat or poultry with the aid ofplastic trays, the tray and content being wrapped in a transparent filmof plastic. Such packs serve not only for storage purposes but also forpresentation purposes. The content of the pack is clearly visiblethrough the transparent film of plastic. Packs of this type aretherefore often offered in refrigerated cabinets of supermarkets or thelike.

The trays are usually molded from polystyrene foam by the thermoformingprocess. During the production process, liquid-impermeable skins areformed on the inside and outside of the tray. In order that any liquidescaping does not collect on the base of the tray, it is also known tomake the foam absorbent by the formation of open-cell regions. The baseof the tray is provided from the inside with a row of holes orapertures, via which liquid can penetrate into the interior of the foamlayer.

If a tray of this type is inclined, there is the risk of the liquidabsorbed in the base within the foam layer running to the border andescaping there. This of course has adverse effects on presentation. Anescape of liquid can only be prevented if the free edge of the border ismade liquid-impermeable.

If, on the other hand, the outer border is sealed, the liquid which runsvia the film or the inside of the tray to the lowest-lying border is nottaken up and absorbed. It collects at the low-lying border between thelatter and the film and impairs the presentation of the product.

SUMMARY OF THE INVENTION

The invention is based on the object of providing a tray for packagingportions of meat or the like and similar foods stored and presented inrefrigerated conditions in which absorbed liquid remains enclosed anddoes not run out even in an inclined position of the tray.

This object is achieved by the features of patent claim 1.

In the case of the tray according to the invention, the inside of thebase has at least one channel completely surrounding a section of thesurface of the base. The channel may be of any desired cross section,for example V-shaped, rectangular, with a curved bottom and straightflanks etc. What is important is that it is a closed or largely closedchannel, which on account of liquid-impermeable walling can serve as acollecting channel for liquid. The channel preferably runs close to theborder of the base or close to the side wall of the tray. As a result,that surface region which serves as an underlay for the content of thepack is surrounded by the channel.

The channel described provides the basis for an advantage over customarypackaging trays, the base of which is provided with a number of holes orpunched perforations, which are covered to a greater or lesser extent bythe content of the pack, for example a piece of meat. The covered holesor punched perforations do not serve for the removal of escaped liquid.Liquid which collects on the base of the tray is only carried away andabsorbed via the remaining holes or punched perforations.

In the case of the tray according to the invention, liquid runs from thesection of the surface surrounded by the channel, which has aliquid-impermeable outer layer or skin, into the channel and collectsthere. The in fact liquid-impermeable walling of the channel is providedaccording to the invention with at least one aperture allowing thepassage of liquid. Along the channel there is preferably a row ofapertures, via which liquid can enter the liquid-absorbent layer of thebase from the channel. Since the apertures are formed only in that flankof the channel which is facing the enclosed surface section, it is alsoonly this section that serves for liquid absorption, while liquid doesnot penetrate into the border region of the tray from the outset.Consequently, liquid also cannot escape via the free edge. The regionbetween the base of the tray and the bottom of the channel isliquid-impermeable due to the forming of the channel. As a result, theliquid absorbed in the surface section of the base enclosed by thechannel remains enclosed, irrespective of the inclination of the tray.

It is conceivable to interrupt the channel at one or more points.Similarly, “bridges” with more or less liquid-permeable regions can beformed between the bottom of the channel and the base of the tray,without significantly impairing the general effect of the channel. Sucha measure may be expedient to compensate at least partially for the lossin strength of the tray caused by the channel.

According to the design of the invention, the aperture may be formed asa hole-shaped punched perforation, which is made in the skin and thelayer lying thereunder, as is the case in known trays. In the lattercase, however, the punched perforations are distributed over the surfaceof the base.

In the present description, reference is made predominantly to trayswhich are molded from polystyrene foam by the thermoforming process and,on account of the production process, have a liquid-impermeable skin onthe inside and outside. It goes without saying, however, that theinvention also applies to those trays which are made up of a pluralityof layers, for example an inner absorbent layer and at least oneliquid-impermeable second layer, covering the inside. It also goeswithout saying that not only open-cell polystyrene foam comes intoconsideration for the absorbent layer but also open-cell foam of otherplastics or an absorbent material acting in a different way.

In order that as large a surface area of the base as possible isenclosed, another design of the invention provides that the channel isformed in the base near the side wall.

The forming of a channel in the base of a tray means of course aweakening of its strength. In order that the weakening is minimized,another design of the invention provides that the channel adopts achanging direction in its path. The channel may, for example, run in azigzagging or meandering form. It may have the shape of a dog's bone. Inprinciple, a wide variety of configurations are possible.

In particular in the case of surface sections covering only part of thebase, it may be advantageous according to a further design of theinvention to form branch channels in the base and possibly also in theinner side wall, via which liquid can flow to the peripheral channel.

In the case of conventional trays, it is disadvantageous if the freeedge of the outwardly bent border of the tray is liquid-permeable. Asmentioned above, in the case of known trays this can cause the liquid toescape and collect between the border and the film. In the case of thetray according to the invention, on the other hand, a liquid-permeableborder is advantageous. Liquid which collects along the film or in someother way in the free border region can then enter the side wall, whichlike the base contains an inner liquid-absorbent layer, via theliquid-permeable edge by capillary action.

The take-up of liquid in the border region of the tray is furtherimproved according to one design of the invention if elevations areformed at intervals on the upper side of the outwardly bent border. Theelevations or protrusions have the effect of creating a gap between thefilm and the border surface, via which liquid can pass more easily overthe border and enter the side wall over the free edge.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention represented in the drawings areexplained in more detail below.

FIG. 1 shows a section through a tray according to the invention.

FIG. 2 shows the plan view of the tray according to FIG. 1.

FIG. 3 shows the plan view of another embodiment of a tray according tothe invention.

FIG. 4 shows the plan view of a third embodiment of a tray according tothe invention.

FIG. 5 shows a plan view of a fourth embodiment of a tray according tothe invention.

FIG. 6 shows a section through the tray according to FIG. 1 along theline 6—6.

FIG. 7 shows a section through the tray according to FIG. 5 along theline 7—7.

FIG. 8 shows the side view of part of the free edge of the side wall ofthe tray according to FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This disclosure of the invention is submitted in furtherance of theconstitutional purposes of the U.S. Patent Laws “to promote the progressof science and useful arts” (Article 1, Section 8).

A tray 10 is represented in FIGS. 1 and 2. It has a base 12 and a sidewall 14, which is given greater strength by external impressions.However, these are not considered in detail. They are state of the art.The side wall 14 has an outwardly bent-away border 16 with a free edge18. It is also shown in FIG. 1 how a transparent film of plastic 20encloses the entire tray 10. The film of plastic 20 is indicated in sucha way as though there were an item, for example a portion of meat or thelike, in the tray 10.

The tray 10, formed in one piece, is produced from polystyrene orsimilar material, to be precise by the thermoforming process. The typeof production has the effect that on the inside and outside of the tray10 there respectively forms a skin 22 and 24, which isliquid-impermeable. The layer of foam lying between is partiallyopen-cell. It is therefore suitable like a sponge for the absorption ofliquid.

As can be seen from FIGS. 1 and 2, the inner bottom surface of the base12 is surrounded by a channel 26, which is formed into the base from itsinside. This is clearly shown by FIG. 6.

The channel 26 has flanks 28, 30 and a bottom 32. They bound the channel26 on the side and from below. As can be seen, the bottom 32 ends at adistance from the lower skin 24 of the base 12. The walling of thechannel is liquid-impermeable, as is the walling of the remainingsections of the tray. Liquid, as indicated at 34, can therefore collectin the channel 26. The region between the bottom 32 of the channel andbase 24 of the tray is liquid-impermeable on account of the forming ofthe channel 26. As a result, the region enclosed by the channel 26 formsa largely closed chamber, which receives the liquid from the channel 26.

However, punched perforations 36 are made at intervals in the flank 30facing the inner surface section 38. These punched perforationspenetrate the skin of the flank 30. They consequently make it possiblefor the liquid 34 to enter into the interior of the base section 38enclosed by the channel 26. As a result, the liquid collecting in thechannel 26 can be absorbed in the base section 38. On the other hand,the channel prevents liquid from penetrating into the side wall 14 ofthe tray 10, even if the tray is arranged such that it is inclined withrespect to the horizontal. Running out of liquid over the border to theoutside is thus avoided.

In FIG. 2 it can be seen that protrusions 39 are formed at intervals onthe upper side of the border 16. These protrusions have the effect thatthe film 20, as shown in FIG. 8, forms in the region of the free edge 18a distance from the border 16, via which liquid can get to the free edge18. Since the free edge is liquid-permeable, consequently has noliquid-impermeable skin, liquid which collects on one side at the border16 can enter via the edge 18 and be absorbed. In this case, the wall 14serves as an absorption volume, its size being adequate in relation tothe amount of liquid occurring to hold the liquid by capillary actionalone. Running out of liquid absorbed in the base section 38 via theborder 14 and the free edge 18 is in any event prevented.

In the case of the tray according to FIG. 3, a peripheral channel 26 ais laid out in a zigzag form. On the flank or channel facing theenclosed section of the surface, punched perforations 36 a are againprovided, similar to the punched perforations 36 in the case of the tray10 according to FIGS. 1 and 2. The zigzag path has the effect that thestrength of the tray is weakened much less than is the case with arectangular path of the channel 26 according to FIG. 2.

FIG. 4 shows a tray 10 b which is constructed in a way similar to thetrays according to FIGS. 1 to 3. A peripheral channel 26 b has a rhombicshape. The 20 enclosed surface section 38 b is in turn provided withpunched perforations 36 b adjacent to the channel 26 b, in a way similarto the punched perforations 36 and 36 a according to FIGS. 1 to 3. Inaddition, branch channels 40 are provided, extending from the corners ofthe base 12 approximately perpendicularly with respect to the associatedsection of the channel 26 b. The four branch channels 40 serve as feedchannels, which convey liquid collecting in neighboring sections of thebase 12 b to the channel 26 b.

In the case of the embodiment according to FIG. 5, the base 12 c of thetray 10 c has a channel 26 c in the shape of a dog's bone, punchedperforations 36 c having been made in the enclosed surface section 38 cor in the channel 26 c, resembling the punched perforations 36 to 36 baccording to the embodiments above. Branch channels 42 are formed on theinner side of the side wall 14 c. They extend from the side wall overthe outer section of the base to the channel 26 c. This can also be seenin the section according to FIG. 7. The branch channels 42 serve asdrainage for liquid in the direction of the channel 26 c, as do furtherbranch channels 44, which are formed in the base 12 c.

It goes without saying that indentations, holes or the like, which servein a conventional way for the take-up of the liquid, may be formed inthe base in addition to the channel in the enclosed volume.

In compliance with the statute, the invention has been described inlanguage more or less specific as to structural and methodical features.It is to be understood, however, that the invention is not limited tothe specific features shown and described, since the means hereindisclosed comprise preferred forms of putting the invention into effect.The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

What is claimed is:
 1. A thermoformed tray for packaging food,comprising: a base and a peripheral side wall, the base and side wallhaving a liquid-impermeable skin on an inside surface and an outsidesurface and a layer of foam between the inside skin and the outsideskin, a plurality of apertures provided through the inside skin over thebase, and the layer of foam lying between the inside skin and theoutside skin being at least partially open-cell and acting in aliquid-absorbing manner, at least one channel, surrounding an enclosedsurface section of the base, is formed into the inside of the base, withflanks and a channel bottom, which has a liquid-impermeable skin, avolume of the base that is assigned to the enclosed surface sectionbeing separated in a liquid-impermeable manner from neighboringsections, and the flank facing the surface section having at least oneaperture allowing a passage of liquid.
 2. The tray as claimed in claim1, characterized in that the aperture is formed by a hole-shaped punchedperforation.
 3. The tray as claimed in claim 1, characterized in thatthe channel is formed in the base near the side wall.
 4. The tray asclaimed in claim 1, characterized in that the channel adopts a changingdirection in its path.
 5. The tray as claimed in claim 4, characterizedin that the channel runs in a zigzagging or meandering form.
 6. The trayas claimed in claim 1, characterized in that the channel has the shapeof a dog's bone.
 7. The tray as claimed in claim 1, characterized inthat branch channels which are connected to the channel are formed inthe base and/or in the side wall and the surfaces bounding the branchchannels are liquid-impermeable.
 8. The tray as claimed in claim 7,characterized in that the branch channels meet the channel almostperpendicularly.
 9. The tray as claimed in claim 1, characterized inthat the free edge of the outwardly bent free border of the side wall isliquid-impermeable.
 10. The tray as claimed in claim 1, characterized inthat elevations are formed at intervals on the upper side of theoutwardly bent border of the side wall.
 11. The tray as claimed in claim2, characterized in that the channel is formed in the base near the sidewall.
 12. The tray as claimed in claim 2, characterized in that thechannel adopts a changing direction in its path.
 13. The tray as claimedin claim 3, characterized in that the channel adopts a changingdirection in its path.
 14. The tray as claimed in claim 3, characterizedin that the channel has the shape of a dog's bone.
 15. The tray asclaimed in claim 8, characterized in that the free edge of the outwardlybent free border of the side wall is liquid-permeable.
 16. The tray asclaimed in claim 2, characterized in that elevations are formed atintervals on the upper side of the outwardly bent border of the sidewall.
 17. The tray as claimed in claim 4, characterized in thatelevations are formed at intervals on the upper side of the outwardlybent border of the side wall.
 18. The tray as claimed in claim 7,characterized in that elevations are formed at intervals on the upperside of the outwardly bent border of the side wall.
 19. The tray asclaimed in claim 8, characterized in that elevations are formed atintervals on the upper side of the outwardly bent border of the sidewall.
 20. The tray as claimed in claim 9, characterized in thatelevations are formed at intervals on the upper side of the outwardlybent border of the side wall.
 21. A thermoformed tray forliquid-secreting foods, comprising: a base having an insideliquid-impermeable layer, an outside liquid-impermeable layer, and aliquid absorbent layer provided between the inside layer and the outsidelayer; a peripheral side wall extending about the base; a channel formedin an inner surface of the base and bounded by the insideliquid-impermeable layer being disposed into the liquid- absorbent layerso as to render the channel liquid-impermeable, the channel defining anenclosed surface section in the base and a liquid-absorbent base portionprovided by the liquid absorbent layer therebelow being separated in aliquid-impermeable manner from any neighboring portion; and at least oneperforation through the inside liquid-impermeable layer provided atleast in part along the channel and configured to allow passage ofliquid from the channel into the liquid-absorbent base portion.
 22. Thetray of claim 21 wherein the base and the peripheral side wall areintegrally formed from a sandwich of the liquid impermeable inner layer,the liquid absorbent layer, and the liquid impermeable outer layer. 23.The tray of claim 21 wherein the channel comprises a non-circular,closed channel.
 24. The tray of claim 21 wherein the channel forms aliquid impermeable wall about the liquid absorbent base portion.
 25. Thetray of claim 21 wherein a plurality of the perforations are providedspaced-apart along the channel via which liquid can enter the liquidabsorbent layer of the liquid absorbent base portion.
 26. The tray ofclaim 21 wherein the channel is thermoformed into the base and theregion between the base of the tray and the bottom of the channel isliquid-impermeable due to forming of the channel.
 27. The tray of claim21 further comprising at least one liquid-impervious branch channelcommunicating with the channel and radiating outwardly of the channelvia which liquid can flow to the channel from the branch channel.